2001 MPV - Nothing when i turn the key

2001 mazda mpv. drove it quite a bit today, then parked and when i went to start it again a brief beep, cd ejected and nothing at all when ignition was turned. Tried a few minutes later and started fine. I noticed that the clock was reset. Just tried to start (hours later) and again nothing at all. Battery is fairly new. I noticed the coolan?t resoviour is empty. Anything I can check before i have to have it towed